Develop Reference

Hiding a <div> and showing a new one in the same spot?

Lets say I have 2 divs, one is hidden, the other is showing. When a button is clicked, I want to use the jQuery fade effect to fade out one div and fade in the hidden div.
So -
<div id="part1">Hello</div>
<div id="part2" style="display: none">Hello2!</div>
<button id="btn1">Click here!</button>
and the JS -
$("#btn1").on("click", function(){
$("#part1").fadeToggle();
$("#part2").fadeToggle();
});
Now, this works, but as you can imagine what happens is that it first hides the 1st div, then shows the second div, and then immediately takes the second div up to the place where the previous div was located.
What can I do about this? I want them to stay in the same position (something like they have here http://kenwheeler.github.io/slick/ in their fade demo.)
Thanks!

You can do it with jQuery. Fade out the first div and fade in the second one in the callback. Like this: http://jsfiddle.net/D2Cw9/
$(".one").fadeOut(500, function() {
$(".two").fadeIn(500, function() {
});
});

One solution would be using absolute positioning on both divs relative to their container.
#parts-container {
position: relative;
}
#part1, #part2 {
position: absolute;
left: 0;
top: 0;
}

Use css position absolute to set them to the same position.

At the time of writing, you have 4 answers that all seem to be correct solutions using CSS positioning. I noticed you have jQuery as a tag, so I thought I'd offer up a different solution.
Have you thought about not actually hiding the div, and replacing it with the other? For example, you could change the CSS class of the div with jQuery:
$('#part1').fadeOut(300, function() {
$('#part1').addClass('part2');
$('#part1').innerHTML('Hello2!');
$('#part1').fadeIn(300, function(){});
});
Of course you should use a synchronous fade to make sure the class change happens while the div is hidden.

It seems that a lot of people answered this question correctly. I would like to add that you can also keep the div and just set the css opacity to 0 using the jQuery UI color animation.
I believe this is yet another option.

Try adding position absolute to both of them and wrapping them in a relative div

Keyframes animation when changed back to display none

So I have a div with an animation using some keyframes. I use javascript to change the default display: none to display:inline when I click on something.
Now when I change it from display: none to display:inline, it does the animation but when I click again to hide it it doesn't. Is there any way to make the keyframe animation play when both shown and hidden? I hope it's clear, thanks in advance.

You can use jQuery,
$(document).ready({
$("a").click(function(e) {
e.preventDefault();
$("div").toggle("slow"); // change to display: block
});
});
DEMO

Sliding from side with jquery (without Jquery UI)

I want to make specialist_pagecontent to appear (slide) from the left, like blindleftin from here but I just can't make it work with this. Actually, the plan is, instead of hide() ideal would be blindLeftOut('fast');hide(), and instead of show() I need show();blindLeftOut('slow'), but as I said, I just can't make blindLeftOut and blindLeftIn work for me.

I think jQuery's animate function might be of use to you.
What you'd need to do is either have a hidden div positioned out of the window added to your HTML (or maybe add it dynamically using jquery on document.ready event, if you prefer) and the use the above mentioned animate function to slide it in and out and bind it to the menu item's click function.
Working Fiddle
Here is a working JSFiddle for you

Give the elements you want to animate in and out a viweport. A layer through which you look to see the elements within. Then set this viewport's overflow property to hidden and give it a specific width/height.
This way you can animate the elements within the viewport so they appear to slide in/out.
Here are the changes I'd make to your JS:
//notice the use of the "active" class to save state
$('.specialist_pagecontent').eq(0).addClass("active").animate({ left : 0 }, 500);
$('.specialist').click(function() {
//stop() is used to stop the current animation, so animations don't queue up if many buttons are clicked rapidly
$('.specialist_pagecontent').filter(".active").removeClass("active").stop(true).animate({ left : '-100%' }, 500);
$('.selected-specialist').removeClass('selected-specialist');
$(this).addClass('selected-specialist');
$('.specialist_pagecontent').eq($(this).index('.specialist')).addClass("active").stop(true).animate({ left : 0 }, 500);
});
And here are my suggested edits to the CSS:
.specialist_pagecontent {
position:absolute;
top:0;
left:-100%;
}
#specialist_lists {
float:left;
border: 1px solid #000000;
position:relative;
width:200px;
height:200px;
overflow:hidden;
}
Here is a demo: http://jsfiddle.net/Jwkw6/1/
This absolutely positions the elements that are to be animated, which is very useful since it removes the elements from the regular flow of the document (meaning it won't trigger whole page redraws when it animates). This also creates the viewport I mentioned, creating a window into which we look to see the animations.

How to make an underlaying element unclickable/deactive?

I have two elements on top of each other. When I click a button on the first div, the second div opens on top of the first div, and what I want to do is to make the underlaying div non-interactive (That I can't click on anything on the underlaying-div as long as the overlaying-div is open).
Javascript code:
$('#button').live('click', function()
{
$('#underlaying-div).fadeTo("fast", 0.7);
$('#overlaying-div).css('display', 'block');
//Do something here to make the underlaying div unclickable
});
$("#overlaying-div").live("click", function() {
$(this).hide();
$('#underlaying-div).fadeTo("slow", 1.0);
//Do something here to make the underlaying div clickable again
});
CSS-code:
#overlay-div
{
position:absolute;
left:0;
top:0;
display:none;
z-index: 20000;
}
I know I can use event.preventDefault() to make sure nothing happens if you click on an element in the underlaying-div, but I'd rather want that nothing happens at all when you for instance hover over an button (with preventDefault(), hover and other stuff still happens).
Any other ways in CSS or javascript/JQuery that can fix this problem??

Not sure of your final product, but if the underlaying div get overlapped by the overlaying in a way that the underlaying div is not visible anymore you could just display:block; the underlaying div.

This is a very old question, but if someone happens upon it, you might find it useful to toggle the pointer-events CSS property of the object you want to disable. You won't need to manually remove click bindings or add any other wrappers. If an object has pointer-events set to 'none', no events will fire when it is clicked.
In jQuery:
$('#underlaying-div).css('pointerEvents', 'none'); // will disable
$('#underlaying-div).css('pointerEvents', 'auto'); // will reenable

You could use unbind to remove the click event handler like this:
$(this).unbind('click'):
My concern is if this works with a live bind but you should at least try it :)

Why don't you use jQuery .fadeIn() and .fadeOut() functions? You have two divs with id="div1" and id="div2" and you have a button in div1 with id="button1" and a button in div2 with id="button2".
CSS code:
#div1 {
//some CSS code without z-index
}
#div2 {
//some CSS code without z-index
visibility:hidden;
}
jQuery code:
$('#button1').click(function(){$('#div1').fadeOut('slow', function(){$('#div2').fadeIn()})})
$('#button2').click(function(){$('#div2').fadeOut('slow', function(){$('#div1').fadeIn()})})

jQuery toggle changes element's width? I don't want it to

I currently have a table that has a width of 94%, and the following toggle set to it:
$(document).ready(function(){
$("#moreinfo").hide();
$("#toggleinfo").click(function () {
$("#moreinfo").toggle('normal');
});
});
It toggles fine, but as soon as you toggle, the width goes really small and I have no idea why. If I remove the hide() it's the right width, but again as soon as I start toggling it, the width automatically resizes.
Just tried the following CSS too:
#moreinfo { width: 94% !IMPORTANT; }
Edit: it seems to completely remove any width applied through CSS when I toggle it
Edit2: Wrapping it inside another div works! Not ideal, but not a bad solution I guess.
Any way to stop this please?

The jQuery toggle() function sets your target element ('#moreinfo' in this case) to display: block. It's just a guess without seeing your CSS or HTML, but I'm picking that the table, when having its display property changed, is being positioned or laid out incorrectly.
You may be able to work around this by wrapping your moreinfo element in another div with display: inline or position: relative? But that's just a guess. Do different browsers show the same result?